William B. "Bill" Regan, who was Mayor Joe Riley's chief legal adviser during most of his tenure, died Thursday morning after an illness. He was 75.

Regan served as the city of Charleston's corporation counsel from December 1975 until January 2003.

In that role he helped Riley and City Council create Charleston Place, Waterfront Park and the S.C. Aquarium. He also helped the city annex Daniel Island and large amounts of the city's western suburbs.

"Every important initiative that occurred during these 27 years had Bill Regan's imprint on it," Riley said.

Regan shared the mayor's Irish heritage and was as jovial as he was knowledgeable. He always stood ready with a witty story or saying, such as his take on his fellow lawyers: "A lawyer who ain't lost any ain't tried many."

Or how attorneys appreciated clients who wanted to fight on principle rather than settle a case. "Lawyers like principle," he would say. "Principle is expensive."

S.C. Supreme Court Justice Jean Toal, whose longtime friendship with Regan began when they attended law school together, noted that Regan's legal career began when he teamed up with Harry Lightsey, who later served as dean of the University of South Carolina's School of Law and as president of the College of Charleston.

Toal said Regan's Irish wit and charm sometimes would obscure how bright a lawyer he was.

"He really was the quintessential professional for local government law," Toal said, "particularly after Home Rule reforms" that gave cities and counties more power in the 1970s.

Toal said Regan came into his own when he teamed up with lawyer Frances Cantwell, who also worked for the city and who Regan later married.

The pair often tried cases before the state Supreme Court.

Charleston lawyer Peter McGee said Regan served as the city's corporation counsel longer than any other, but his personality was as noteworthy as his longevity.

"In my 50-plus years at the bar, it's tough to think of any lawyer whose company was so much enjoyed as Bill's," McGee said.

"His wonderful sense of humor, the great stories he told --most of which were true -- simply endeared him to us."

"Bill Regan's happy disposition, his wonderful wit and the joyfulness that he exuded so positively affected all who had the pleasure of working with him," Riley said. "His death is the cause of great sadness for us all."

All flags on city buildings will be flown at half-staff until after Regan's funeral. Arrangements are being handled by James A. McAlister Funerals & Cremation.